Miss firing '85 85

[swrupert83]

So i recently got this engine working, and since the first time it ran... it ran well. the only thing i noticed is that when i checked the spark the # 1 was weaker than the rest. Then this weekend I fired her up and she was rough, and then getting rougher, then she wouldn't stay running with low rpm's and she was kicking and flopping about even at higher rev's. when i removed the #1 plug she would run ok with out misses and knocks, but as soon as i put the boot back on #1 the miss-firing began again.

since the 85 is a three cyclinder, but the CDI (???) boxes both have two wires i swapped the boxes and connections. now she purrs like a kitten, in fact runs better ever than before. My only concern is that there may be some unforscene consequence to this swap. also what made the other one partially sh** the bed, or maybe.... (new thought) now the box (both wires) on # three is not working at all ..possibly
i'll have to check that this weekend?

 

[maxum247]

Re: Miss firing '85 85

Sounds like your in good shape that's the nice thing about the 3 cylinder you carry a spare CD module so to speak!
By switching the module for 3 to 1 and 2 they are both now firing and by switching the module from 1 and 2 to 3 your useing the one good side of that module.
Something about circuits in the module, two seperate one's I beleive, so one half of your module goes bad the other half is still useable.

 

[swrupert83]

Re: Miss firing '85 85

yeah i kinda figured, but still wonding why it just went. and wondering why it went bad slowly over the course of a few minutes.

thanks

 

[maxum247]

Re: Miss firing '85 85

Do a search on CD modules.
You may find the answer as to why modules fail there!

 

[jerryjerry05]

Re: Miss firing '85 85

NO REASON why they go bad is the final answer.It could be fine 1 minute and gone the next.
My boat was new 1988 and had 5-10 hours and ran great. We went fishing and shut the motors down and restarted and the port motor was missing.
Took it to work(I worked at the dealership) and tested and had to change the packs around and haven't hadf a bit of a problem since.
You need to make sure all grounds and contacts are tight.That causes a lot of problems.Jerry